The BeagleBoard is yet another fan-less, Open Source hardware single-board computer. It’s produced by Texas Instruments (TI) and Digi-Key, and uses the ARM Cortex A8 processor clocked at 600 MHz. The board is just 7.6×7.6 cm2 (3×3 inch2) in size and comes coloured in what I like to call as the TI Red. It can run Linux, Risc OS, Symbian, Nokia’s Maemo OS and Android. The board also supports OpenGL ES 2.0 through its PowerVR SGX530 GPU.
The BeagleBoard comes in BeagleBoard-xM and BeagleBone versions. Up to four expansion boards, called capes, can be added to the BeagleBoard. Other expansion boards include the BeagleJuice—a Li-ion battery pack.
The BeagleBone is a stripped-down version of the BeagleBoard. It is amazingly compact at 8.6×5.3 cm2 (3.4×2.1 inch2) and sold online for Rs. 6560. On the other hand, the BeagleBoard XM is available for Rs. 10,920.
STMicroelectronics’ STM32 Discovery
This board from the STMicroelectronics stable is yet another inexpensive development board that runs on ARM Cortex-M3 prototyping platform. The STM32 Discovery line comes in STM32L and STM32VL versions.
The STM32L Discovery is an ultra-low-power discovery board based on the STM32L core [STM32L1xxx] and includes an ST-Link/V2 embedded debugging tool interface, an LCD (24 segments, four commons), LEDs, pushbuttons and a linear touch sensor. Non-intrusive debug is possible with the in-circuit debugger available on STM32 Value Line Discovery. The kit can also be used as an ST-link for your own board.
The board’s power supply can be either through the USB bus or an external 3.3V or 5V supply. The STM32 is also said to be one of the lowest power-consuming, 32-bit, 72MHz computer in the market today. It costs around Rs. 940 in India.
If you are new to STM32 Discovery boards, you can check out numerous examples based on this board at www.st.com/stm32-discovery.
The STM32VL Value Line board is priced at ` 865 in India. Unlike the Discovery kit, it is based on the STM32F core (STM32F1xxx). The STM32L is meant for ultra-low-power devices and hence uses a different core.
Keep in mind that the STM32L and STM32VL are different families of boards. These are not as compatible as their almost similar names suggest. Debugging is different for both these boards.
TI MSP430 Launchpad
Unveiled in 2010, this board is a development platform for Texas Instruments’ MSP430 line of low-cost microcontrollers. It is a mixed-signal integrated circuit based development board that costs just Rs. 393. The kit features built-in flash emulation for debugging and programming and a 14- or 20-pin dual-in-line package (DIP) socket. It also comes with ten general-purpose input-output (GPIO) pins. GPIO pins are generic pins. Their behaviour can be controlled through software.
“The USP for the MSP430 is ultra-low power consumption (TI’s online document shows that at 0.1 per cent active, an MSP430 can last for over 20 years on a 200mAh coin cell). It is used as an ultra-low-power MCU in niche devices such as blood group meters, general metering, home automation and wireless smoke detectors. We do have success with other architectures as well, but 70 per cent of our success can be attributed to the MSP430. That’s why we have also launched the low-cost Launchpad based on the MSP430, which sells for $4.30. It has all the debug capabilities and one can do all the prototyping on the Launchpad itself,” says Shailesh Thakurdesai, general manager-business development, Texas Instruments.
Each Launchpad board comes bundled with some extras. In addition to the onboard 32.768kHz clock crystal, you get half-a-metre USB cable, two-pin headers and two-pin sockets for the pin breakout pads, two different MSP430s (MSP430G2553 and MSP430G2452), and two free integrated development environments (Code Composer Studio 4 and IAR Embedded Workbench Kickstart). Note that the IAR Embedded Workbench Kickstart has a 4k or 8k code limitation depending on the processor used. The Launchpad board also works with any programming tool that supports the two-wire Spy-bi-Wire interface.
MSP430G2553. It’s a low-power, 16-bit MSP430 microcontroller with an 8-channel, 10-bit analogue-to-digital converter (ADC), on-chip comparator, touch-sense-enabled inputs/outputs (I/Os), universal serial communication interface, 16kB flash memory and 512 bytes of RAM (preloaded with a sample program).
MSP430G2452. This too is a low-power, 16-bit MSP430 microcontroller with an 8-channel, 10-bit ADC, on-chip comparator, touch-sense-enabled I/Os and universal serial interface but it has an 8kB flash memory and 256 bytes of SRAM.